drivers/media/test-drivers/vidtv/vidtv_s302m.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Vidtv serves as a reference DVB driver and helps validate the existing APIs
   4  * in the media subsystem. It can also aid developers working on userspace
   5  * applications.
   6  *
   7  * This file contains the code for an AES3 (also known as AES/EBU) encoder.
   8  * It is based on EBU Tech 3250 and SMPTE 302M technical documents.
   9  *
  10  * This encoder currently supports 16bit AES3 subframes using 16bit signed
  11  * integers.
  12  *
  13  * Note: AU stands for Access Unit, and AAU stands for Audio Access Unit
  14  *
  15  * Copyright (C) 2020 Daniel W. S. Almeida
  16  */
  17
  18 #define pr_fmt(fmt) KBUILD_MODNAME ":%s, %d: " fmt, __func__, __LINE__
  19
  20 #include <linux/bug.h>
  21 #include <linux/crc32.h>
  22 #include <linux/fixp-arith.h>
  23 #include <linux/jiffies.h>
  24 #include <linux/kernel.h>
  25 #include <linux/math64.h>
  26 #include <linux/printk.h>
  27 #include <linux/ratelimit.h>
  28 #include <linux/slab.h>
  29 #include <linux/string.h>
  30 #include <linux/types.h>
  31 #include <linux/vmalloc.h>
  32
  33 #include "vidtv_common.h"
  34 #include "vidtv_encoder.h"
  35 #include "vidtv_s302m.h"
  36
  37 #define S302M_SAMPLING_RATE_HZ 48000
  38 #define PES_PRIVATE_STREAM_1 0xbd  /* PES: private_stream_1 */
  39 #define S302M_BLOCK_SZ 192
  40 #define S302M_SIN_LUT_NUM_ELEM 1024
  41
  42 /* these are retrieved empirically from ffmpeg/libavcodec */
  43 #define FF_S302M_DEFAULT_NUM_FRAMES 1115
  44 #define FF_S302M_DEFAULT_PTS_INCREMENT 2090
  45 #define FF_S302M_DEFAULT_PTS_OFFSET 100000
  46
  47 /* Used by the tone generator: number of samples for PI */
  48 #define PI              180
  49
  50 static const u8 reverse[256] = {
  51         /* from ffmpeg */
  52         0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0, 0x10, 0x90, 0x50, 0xD0,
  53         0x30, 0xB0, 0x70, 0xF0, 0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8,
  54         0x18, 0x98, 0x58, 0xD8, 0x38, 0xB8, 0x78, 0xF8, 0x04, 0x84, 0x44, 0xC4,
  55         0x24, 0xA4, 0x64, 0xE4, 0x14, 0x94, 0x54, 0xD4, 0x34, 0xB4, 0x74, 0xF4,
  56         0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC, 0x1C, 0x9C, 0x5C, 0xDC,
  57         0x3C, 0xBC, 0x7C, 0xFC, 0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2, 0x62, 0xE2,
  58         0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2, 0x0A, 0x8A, 0x4A, 0xCA,
  59         0x2A, 0xAA, 0x6A, 0xEA, 0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA,
  60         0x06, 0x86, 0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6, 0x16, 0x96, 0x56, 0xD6,
  61         0x36, 0xB6, 0x76, 0xF6, 0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE,
  62         0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE, 0x01, 0x81, 0x41, 0xC1,
  63         0x21, 0xA1, 0x61, 0xE1, 0x11, 0x91, 0x51, 0xD1, 0x31, 0xB1, 0x71, 0xF1,
  64         0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9, 0x19, 0x99, 0x59, 0xD9,
  65         0x39, 0xB9, 0x79, 0xF9, 0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5,
  66         0x15, 0x95, 0x55, 0xD5, 0x35, 0xB5, 0x75, 0xF5, 0x0D, 0x8D, 0x4D, 0xCD,
  67         0x2D, 0xAD, 0x6D, 0xED, 0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD, 0x7D, 0xFD,
  68         0x03, 0x83, 0x43, 0xC3, 0x23, 0xA3, 0x63, 0xE3, 0x13, 0x93, 0x53, 0xD3,
  69         0x33, 0xB3, 0x73, 0xF3, 0x0B, 0x8B, 0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB,
  70         0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB, 0x07, 0x87, 0x47, 0xC7,
  71         0x27, 0xA7, 0x67, 0xE7, 0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7,
  72         0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF, 0x1F, 0x9F, 0x5F, 0xDF,
  73         0x3F, 0xBF, 0x7F, 0xFF,
  74 };
  75
  76 struct tone_duration {
  77         enum musical_notes note;
  78         int duration;
  79 };
  80
  81 #define COMPASS 100 /* beats per minute */
  82 static const struct tone_duration beethoven_fur_elise[] = {
  83         { NOTE_SILENT, 512},
  84         { NOTE_E_6, 128},  { NOTE_DS_6, 128}, { NOTE_E_6, 128},
  85         { NOTE_DS_6, 128}, { NOTE_E_6, 128},  { NOTE_B_5, 128},
  86         { NOTE_D_6, 128},  { NOTE_C_6, 128},  { NOTE_A_3, 128},
  87         { NOTE_E_4, 128},  { NOTE_A_4, 128},  { NOTE_C_5, 128},
  88         { NOTE_E_5, 128},  { NOTE_A_5, 128},  { NOTE_E_3, 128},
  89         { NOTE_E_4, 128},  { NOTE_GS_4, 128}, { NOTE_E_5, 128},
  90         { NOTE_GS_5, 128}, { NOTE_B_5, 128},  { NOTE_A_3, 128},
  91         { NOTE_E_4, 128},  { NOTE_A_4, 128},  { NOTE_E_5, 128},
  92         { NOTE_E_6, 128},  { NOTE_DS_6, 128}, { NOTE_E_6, 128},
  93         { NOTE_DS_6, 128}, { NOTE_E_6, 128},  { NOTE_B_5, 128},
  94         { NOTE_D_6, 128},  { NOTE_C_6, 128},  { NOTE_A_3, 128},
  95         { NOTE_E_4, 128},  { NOTE_A_4, 128},  { NOTE_C_5, 128},
  96         { NOTE_E_5, 128},  { NOTE_A_5, 128},  { NOTE_E_3, 128},
  97         { NOTE_E_4, 128},  { NOTE_GS_4, 128}, { NOTE_E_5, 128},
  98         { NOTE_C_6, 128},  { NOTE_B_5, 128},  { NOTE_A_3, 128},
  99         { NOTE_E_4, 128},  { NOTE_A_4, 128},  { NOTE_SILENT, 128},
 100
 101         { NOTE_E_6, 128},  { NOTE_DS_6, 128}, { NOTE_E_6, 128},
 102         { NOTE_DS_6, 128}, { NOTE_E_6, 128},  { NOTE_B_5, 128},
 103         { NOTE_D_6, 128},  { NOTE_C_6, 128},  { NOTE_A_3, 128},
 104         { NOTE_E_4, 128},  { NOTE_A_4, 128},  { NOTE_C_5, 128},
 105         { NOTE_E_5, 128},  { NOTE_A_5, 128},  { NOTE_E_3, 128},
 106         { NOTE_E_4, 128},  { NOTE_GS_4, 128}, { NOTE_E_5, 128},
 107         { NOTE_GS_5, 128}, { NOTE_B_5, 128},  { NOTE_A_3, 128},
 108         { NOTE_E_4, 128},  { NOTE_A_4, 128},  { NOTE_E_5, 128},
 109         { NOTE_E_6, 128},  { NOTE_DS_6, 128}, { NOTE_E_6, 128},
 110         { NOTE_DS_6, 128}, { NOTE_E_6, 128},  { NOTE_B_5, 128},
 111         { NOTE_D_6, 128},  { NOTE_C_6, 128},  { NOTE_A_3, 128},
 112         { NOTE_E_4, 128},  { NOTE_A_4, 128},  { NOTE_C_5, 128},
 113         { NOTE_E_5, 128},  { NOTE_A_5, 128},  { NOTE_E_3, 128},
 114         { NOTE_E_4, 128},  { NOTE_GS_4, 128}, { NOTE_E_5, 128},
 115         { NOTE_C_6, 128},  { NOTE_B_5, 128},  { NOTE_A_3, 128},
 116         { NOTE_E_4, 128},  { NOTE_A_4, 128},  { NOTE_B_4, 128},
 117         { NOTE_C_5, 128},  { NOTE_D_5, 128},  { NOTE_C_4, 128},
 118         { NOTE_G_4, 128},  { NOTE_C_5, 128},  { NOTE_G_4, 128},
 119         { NOTE_F_5, 128},  { NOTE_E_5, 128},  { NOTE_G_3, 128},
 120         { NOTE_G_4, 128},  { NOTE_B_3, 128},  { NOTE_F_4, 128},
 121         { NOTE_E_5, 128},  { NOTE_D_5, 128},  { NOTE_A_3, 128},
 122         { NOTE_E_4, 128},  { NOTE_A_4, 128},  { NOTE_E_4, 128},
 123         { NOTE_D_5, 128},  { NOTE_C_5, 128},  { NOTE_E_3, 128},
 124         { NOTE_E_4, 128},  { NOTE_E_5, 128},  { NOTE_E_5, 128},
 125         { NOTE_E_6, 128},  { NOTE_E_5, 128},  { NOTE_E_6, 128},
 126         { NOTE_E_5, 128},  { NOTE_E_5, 128},  { NOTE_DS_5, 128},
 127         { NOTE_E_5, 128},  { NOTE_DS_6, 128}, { NOTE_E_6, 128},
 128         { NOTE_DS_5, 128}, { NOTE_E_5, 128},  { NOTE_DS_6, 128},
 129         { NOTE_E_6, 128},  { NOTE_DS_6, 128}, { NOTE_E_6, 128},
 130         { NOTE_DS_6, 128}, { NOTE_E_6, 128},  { NOTE_B_5, 128},
 131         { NOTE_D_6, 128},  { NOTE_C_6, 128},  { NOTE_A_3, 128},
 132         { NOTE_E_4, 128},  { NOTE_A_4, 128},  { NOTE_C_5, 128},
 133         { NOTE_E_5, 128},  { NOTE_A_5, 128},  { NOTE_E_3, 128},
 134         { NOTE_E_4, 128},  { NOTE_GS_4, 128}, { NOTE_E_5, 128},
 135         { NOTE_GS_5, 128}, { NOTE_B_5, 128},  { NOTE_A_3, 128},
 136         { NOTE_E_4, 128},  { NOTE_A_4, 128},  { NOTE_E_5, 128},
 137         { NOTE_E_6, 128},  { NOTE_DS_6, 128}, { NOTE_E_6, 128},
 138         { NOTE_DS_6, 128}, { NOTE_E_6, 128},  { NOTE_B_5, 128},
 139         { NOTE_D_6, 128},  { NOTE_C_6, 128},  { NOTE_A_3, 128},
 140         { NOTE_E_4, 128},  { NOTE_A_4, 128},  { NOTE_C_5, 128},
 141         { NOTE_E_5, 128},  { NOTE_A_5, 128},  { NOTE_E_3, 128},
 142         { NOTE_E_4, 128},  { NOTE_GS_4, 128}, { NOTE_E_5, 128},
 143         { NOTE_C_6, 128},  { NOTE_B_5, 128},  { NOTE_A_5, 512},
 144         { NOTE_SILENT, 256},
 145 };
 146
 147 static struct vidtv_access_unit *vidtv_s302m_access_unit_init(struct vidtv_access_unit *head)
 148 {
 149         struct vidtv_access_unit *au;
 150
 151         au = kzalloc(sizeof(*au), GFP_KERNEL);
 152         if (!au)
 153                 return NULL;
 154
 155         if (head) {
 156                 while (head->next)
 157                         head = head->next;
 158
 159                 head->next = au;
 160         }
 161
 162         return au;
 163 }
 164
 165 static void vidtv_s302m_access_unit_destroy(struct vidtv_encoder *e)
 166 {
 167         struct vidtv_access_unit *head = e->access_units;
 168         struct vidtv_access_unit *tmp = NULL;
 169
 170         while (head) {
 171                 tmp = head;
 172                 head = head->next;
 173                 kfree(tmp);
 174         }
 175
 176         e->access_units = NULL;
 177 }
 178
 179 static void vidtv_s302m_alloc_au(struct vidtv_encoder *e)
 180 {
 181         struct vidtv_access_unit *sync_au = NULL;
 182         struct vidtv_access_unit *temp = NULL;
 183
 184         if (e->sync && e->sync->is_video_encoder) {
 185                 sync_au = e->sync->access_units;
 186
 187                 while (sync_au) {
 188                         temp = vidtv_s302m_access_unit_init(e->access_units);
 189                         if (!e->access_units)
 190                                 e->access_units = temp;
 191
 192                         sync_au = sync_au->next;
 193                 }
 194
 195                 return;
 196         }
 197
 198         e->access_units = vidtv_s302m_access_unit_init(NULL);
 199 }
 200
 201 static void
 202 vidtv_s302m_compute_sample_count_from_video(struct vidtv_encoder *e)
 203 {
 204         struct vidtv_access_unit *sync_au = e->sync->access_units;
 205         struct vidtv_access_unit *au = e->access_units;
 206         u32 sample_duration_usecs;
 207         u32 vau_duration_usecs;
 208         u32 s;
 209
 210         vau_duration_usecs    = USEC_PER_SEC / e->sync->sampling_rate_hz;
 211         sample_duration_usecs = USEC_PER_SEC / e->sampling_rate_hz;
 212
 213         while (au && sync_au) {
 214                 s = DIV_ROUND_UP(vau_duration_usecs, sample_duration_usecs);
 215                 au->num_samples = s;
 216                 au = au->next;
 217                 sync_au = sync_au->next;
 218         }
 219 }
 220
 221 static void vidtv_s302m_compute_pts_from_video(struct vidtv_encoder *e)
 222 {
 223         struct vidtv_access_unit *au = e->access_units;
 224         struct vidtv_access_unit *sync_au = e->sync->access_units;
 225
 226         /* use the same pts from the video access unit*/
 227         while (au && sync_au) {
 228                 au->pts = sync_au->pts;
 229                 au = au->next;
 230                 sync_au = sync_au->next;
 231         }
 232 }
 233
 234 static u16 vidtv_s302m_get_sample(struct vidtv_encoder *e)
 235 {
 236         u16 sample;
 237         int pos;
 238         struct vidtv_s302m_ctx *ctx = e->ctx;
 239
 240         if (!e->src_buf) {
 241                 /*
 242                  * Simple tone generator: play the tones at the
 243                  * beethoven_fur_elise array.
 244                  */
 245                 if (ctx->last_duration <= 0) {
 246                         if (e->src_buf_offset >= ARRAY_SIZE(beethoven_fur_elise))
 247                                 e->src_buf_offset = 0;
 248
 249                         ctx->last_tone = beethoven_fur_elise[e->src_buf_offset].note;
 250                         ctx->last_duration = beethoven_fur_elise[e->src_buf_offset].duration *
 251                                              S302M_SAMPLING_RATE_HZ / COMPASS / 5;
 252                         e->src_buf_offset++;
 253                         ctx->note_offset = 0;
 254                 } else {
 255                         ctx->last_duration--;
 256                 }
 257
 258                 /* Handle pause notes */
 259                 if (!ctx->last_tone)
 260                         return 0x8000;
 261
 262                 pos = (2 * PI * ctx->note_offset * ctx->last_tone) / S302M_SAMPLING_RATE_HZ;
 263                 ctx->note_offset++;
 264
 265                 return (fixp_sin32(pos % (2 * PI)) >> 16) + 0x8000;
 266         }
 267
 268         /* bug somewhere */
 269         if (e->src_buf_offset > e->src_buf_sz) {
 270                 pr_err_ratelimited("overflow detected: %d > %d, wrapping.\n",
 271                                    e->src_buf_offset,
 272                                    e->src_buf_sz);
 273
 274                 e->src_buf_offset = 0;
 275         }
 276
 277         if (e->src_buf_offset >= e->src_buf_sz) {
 278                 /* let the source know we are out of data */
 279                 if (e->last_sample_cb)
 280                         e->last_sample_cb(e->sample_count);
 281
 282                 e->src_buf_offset = 0;
 283         }
 284
 285         sample = *(u16 *)(e->src_buf + e->src_buf_offset);
 286
 287         return sample;
 288 }
 289
 290 static u32 vidtv_s302m_write_frame(struct vidtv_encoder *e,
 291                                    u16 sample)
 292 {
 293         struct vidtv_s302m_ctx *ctx = e->ctx;
 294         struct vidtv_s302m_frame_16 f = {};
 295         u32 nbytes = 0;
 296
 297         /* from ffmpeg: see s302enc.c */
 298
 299         u8 vucf = ctx->frame_index == 0 ? 0x10 : 0;
 300
 301         f.data[0] = sample & 0xFF;
 302         f.data[1] = (sample & 0xFF00) >>  8;
 303         f.data[2] = ((sample & 0x0F)  <<  4) | vucf;
 304         f.data[3] = (sample & 0x0FF0) >>  4;
 305         f.data[4] = (sample & 0xF000) >> 12;
 306
 307         f.data[0] = reverse[f.data[0]];
 308         f.data[1] = reverse[f.data[1]];
 309         f.data[2] = reverse[f.data[2]];
 310         f.data[3] = reverse[f.data[3]];
 311         f.data[4] = reverse[f.data[4]];
 312
 313         nbytes += vidtv_memcpy(e->encoder_buf,
 314                                e->encoder_buf_offset,
 315                                VIDTV_S302M_BUF_SZ,
 316                                &f,
 317                                sizeof(f));
 318
 319         e->encoder_buf_offset += nbytes;
 320
 321         ctx->frame_index++;
 322         if (ctx->frame_index >= S302M_BLOCK_SZ)
 323                 ctx->frame_index = 0;
 324
 325         return nbytes;
 326 }
 327
 328 static u32 vidtv_s302m_write_h(struct vidtv_encoder *e, u32 p_sz)
 329 {
 330         struct vidtv_smpte_s302m_es h = {};
 331         u32 nbytes = 0;
 332
 333         /* 2 channels, ident: 0, 16 bits per sample */
 334         h.bitfield = cpu_to_be32((p_sz << 16));
 335
 336         nbytes += vidtv_memcpy(e->encoder_buf,
 337                                e->encoder_buf_offset,
 338                                e->encoder_buf_sz,
 339                                &h,
 340                                sizeof(h));
 341
 342         e->encoder_buf_offset += nbytes;
 343         return nbytes;
 344 }
 345
 346 static void vidtv_s302m_write_frames(struct vidtv_encoder *e)
 347 {
 348         struct vidtv_access_unit *au = e->access_units;
 349         struct vidtv_s302m_ctx *ctx = e->ctx;
 350         u32 nbytes_per_unit = 0;
 351         u32 nbytes = 0;
 352         u32 au_sz = 0;
 353         u16 sample;
 354         u32 j;
 355
 356         while (au) {
 357                 au_sz = au->num_samples *
 358                         sizeof(struct vidtv_s302m_frame_16);
 359
 360                 nbytes_per_unit = vidtv_s302m_write_h(e, au_sz);
 361
 362                 for (j = 0; j < au->num_samples; ++j) {
 363                         sample = vidtv_s302m_get_sample(e);
 364                         nbytes_per_unit += vidtv_s302m_write_frame(e, sample);
 365
 366                         if (e->src_buf)
 367                                 e->src_buf_offset += sizeof(u16);
 368
 369                         e->sample_count++;
 370                 }
 371
 372                 au->nbytes = nbytes_per_unit;
 373
 374                 if (au_sz + sizeof(struct vidtv_smpte_s302m_es) != nbytes_per_unit) {
 375                         pr_warn_ratelimited("write size was %u, expected %zu\n",
 376                                             nbytes_per_unit,
 377                                             au_sz + sizeof(struct vidtv_smpte_s302m_es));
 378                 }
 379
 380                 nbytes += nbytes_per_unit;
 381                 au->offset = nbytes - nbytes_per_unit;
 382
 383                 nbytes_per_unit = 0;
 384                 ctx->au_count++;
 385
 386                 au = au->next;
 387         }
 388 }
 389
 390 static void *vidtv_s302m_encode(struct vidtv_encoder *e)
 391 {
 392         struct vidtv_s302m_ctx *ctx = e->ctx;
 393
 394         /*
 395          * According to SMPTE 302M, an audio access unit is specified as those
 396          * AES3 words that are associated with a corresponding video frame.
 397          * Therefore, there is one audio access unit for every video access unit
 398          * in the corresponding video encoder ('sync'), using the same values
 399          * for PTS as used by the video encoder.
 400          *
 401          * Assuming that it is also possible to send audio without any
 402          * associated video, as in a radio-like service, a single audio access unit
 403          * is created with values for 'num_samples' and 'pts' taken empirically from
 404          * ffmpeg
 405          */
 406
 407         vidtv_s302m_access_unit_destroy(e);
 408         vidtv_s302m_alloc_au(e);
 409
 410         if (e->sync && e->sync->is_video_encoder) {
 411                 vidtv_s302m_compute_sample_count_from_video(e);
 412                 vidtv_s302m_compute_pts_from_video(e);
 413         } else {
 414                 e->access_units->num_samples = FF_S302M_DEFAULT_NUM_FRAMES;
 415                 e->access_units->pts = (ctx->au_count * FF_S302M_DEFAULT_PTS_INCREMENT) +
 416                                        FF_S302M_DEFAULT_PTS_OFFSET;
 417         }
 418
 419         vidtv_s302m_write_frames(e);
 420
 421         return e->encoder_buf;
 422 }
 423
 424 static u32 vidtv_s302m_clear(struct vidtv_encoder *e)
 425 {
 426         struct vidtv_access_unit *au = e->access_units;
 427         u32 count = 0;
 428
 429         while (au) {
 430                 count++;
 431                 au = au->next;
 432         }
 433
 434         vidtv_s302m_access_unit_destroy(e);
 435         memset(e->encoder_buf, 0, VIDTV_S302M_BUF_SZ);
 436         e->encoder_buf_offset = 0;
 437
 438         return count;
 439 }
 440
 441 struct vidtv_encoder
 442 *vidtv_s302m_encoder_init(struct vidtv_s302m_encoder_init_args args)
 443 {
 444         u32 priv_sz = sizeof(struct vidtv_s302m_ctx);
 445         struct vidtv_s302m_ctx *ctx;
 446         struct vidtv_encoder *e;
 447
 448         e = kzalloc(sizeof(*e), GFP_KERNEL);
 449         if (!e)
 450                 return NULL;
 451
 452         e->id = S302M;
 453
 454         if (args.name)
 455                 e->name = kstrdup(args.name, GFP_KERNEL);
 456
 457         e->encoder_buf = vzalloc(VIDTV_S302M_BUF_SZ);
 458         e->encoder_buf_sz = VIDTV_S302M_BUF_SZ;
 459         e->encoder_buf_offset = 0;
 460
 461         e->sample_count = 0;
 462
 463         e->src_buf = (args.src_buf) ? args.src_buf : NULL;
 464         e->src_buf_sz = (args.src_buf) ? args.src_buf_sz : 0;
 465         e->src_buf_offset = 0;
 466
 467         e->is_video_encoder = false;
 468
 469         ctx = kzalloc(priv_sz, GFP_KERNEL);
 470         if (!ctx) {
 471                 kfree(e);
 472                 return NULL;
 473         }
 474
 475         e->ctx = ctx;
 476         ctx->last_duration = 0;
 477
 478         e->encode = vidtv_s302m_encode;
 479         e->clear = vidtv_s302m_clear;
 480
 481         e->es_pid = cpu_to_be16(args.es_pid);
 482         e->stream_id = cpu_to_be16(PES_PRIVATE_STREAM_1);
 483
 484         e->sync = args.sync;
 485         e->sampling_rate_hz = S302M_SAMPLING_RATE_HZ;
 486
 487         e->last_sample_cb = args.last_sample_cb;
 488
 489         e->destroy = vidtv_s302m_encoder_destroy;
 490
 491         if (args.head) {
 492                 while (args.head->next)
 493                         args.head = args.head->next;
 494
 495                 args.head->next = e;
 496         }
 497
 498         e->next = NULL;
 499
 500         return e;
 501 }
 502
 503 void vidtv_s302m_encoder_destroy(struct vidtv_encoder *e)
 504 {
 505         if (e->id != S302M) {
 506                 pr_err_ratelimited("Encoder type mismatch, skipping.\n");
 507                 return;
 508         }
 509
 510         vidtv_s302m_access_unit_destroy(e);
 511         kfree(e->name);
 512         vfree(e->encoder_buf);
 513         kfree(e->ctx);
 514         kfree(e);
 515 }